Why are there such animals as pigs in the world?

Pigs are omnivorous mammals. Fat body, short limbs, long nose, edible meat, skin, short limbs, gentle temperament, strong adaptability, easy to raise, fast reproduction, black, white, sauce red or black and white flowers and other colors. Breeding can be carried out 5- 12 months after birth, and the pregnancy is about 4 months. The average life expectancy is 20 years. It is one of five animals. In the zodiac, the pork chop comes last, which is called hai. There are many allusions and customs about pigs.

You Zhu is called "Yin Zhong", "Tang Ang", "Black-faced Wolf" and "Black Lord". In ancient times, it was called "Gui", also known as "Yu" and "Gui", also known as "Gang Gui". According to reports from the ruling and opposition parties, people in Hongzhou in the Tang Dynasty raised pigs to get rich, which was called "Tang Ang". Yun Xian Miscellaneous Notes in the Tang Dynasty quoted Cheng Ping's Old Edition: "A black-faced lang, also known as a pig." On the land of China, as early as the matriarchal clan commune period, domestic animals such as pigs and dogs have been raised. The pottery pigs unearthed from Hemudu Neolithic cultural site in Yuyao, Zhejiang Province are very similar in shape to the current domestic pigs, indicating that the domestication of pig farms was in the primary stage at that time.

The eating behavior of pigs includes eating and drinking, and has various age characteristics. Pigs are born with the genetic characteristics of arching soil, and arching soil for food is a remarkable feature of pig feeding behavior. The pig's nose is a highly developed organ, and the sense of smell plays a decisive role in digging the soil to find food. Although the diet of pigs in modern piggery is very balanced, pigs also show the characteristics of arch feeding. Every time they are fed, they try to occupy a favorable position in the trough. Sometimes they step on the trough with their forelimbs to eat. If the trough is easy to access, some pigs even get into the trough and stand in a corner of the trough, just like a wild boar arching for food, arching along the trough with a kiss, stirring up the food and scattering it all over the floor. Pigs are selective in their intake of food, and especially like sweets. The study found that non-breastfed newborn piglets like sweets. Compared with powder, pigs like to eat granular substances; Compared with wet feed, pigs like to eat wet feed and spend less time. The feed intake of pigs is competitive, and pigs fed in groups eat more, eat faster and gain more weight than pigs fed alone. Pigs eat 6-8 times during the day, 1-3 times more than at night. The duration of each feeding is 10-20 minutes, and it is less than 10 minutes when feeding is restricted. They eat casually, not only for a long time, but also show the hobbies and personality of every pig. The sucking times of piglets every day and night vary with age, ranging from 15 times to 25 times, accounting for 10% ~ 20% of the total day and night time. The feed intake and frequency of big pigs increase with the increase of body weight. In most cases, drinking water and feeding are done at the same time. The water consumption of pigs is quite large. Piglets need to drink water after birth, mainly from the water in breast milk. When piglets eat feed, the water consumption is about twice that of dry feed, that is, the ratio of water to feed is 2: 1. In addition to feed ingredients, the water consumption of adult pigs depends largely on the environmental temperature. Piglets who eat mixed feed drink 9 ~ 10 times every day and night, and eat wet feed 2 ~ 3 times on average. Pigs who eat dry feed need to drink water immediately after each feeding. Pigs who eat freely generally eat and drink alternately until they are full. Limit feeding pigs to drink water after eating. Piglets can learn to use automatic drinking fountains before they are six months old.

Second, excretion behavior.

Pigs don't defecate where they eat and sleep, which is the nature left by their ancestors, because wild boars don't shit and pee near their nests to avoid being discovered by enemy animals. Under good management conditions, pigs are the cleanest animals among domestic animals. Pigs can keep their nests clean and excrete feces and urine in a fixed place far away from the nests. Pigs excrete feces and urine for a certain time and area. Generally, when they drink water or lie down after meals, they will choose dark, wet or dirty corners to excrete feces and urine, which is influenced by neighboring pigs. It is observed that growing pigs do not defecate during feeding, and begin to defecate 1 ~ 2 times about 5 minutes after satiety. Most of them defecate first and then urinate, and some of them excrete first and then feed, but most of them urinate first and then defecate. During the feeding interval, pigs usually defecate 2 ~ 3 times at night, with the largest amount of excretion in the morning, and the nighttime excretion activity time of pigs accounts for the total time of day and night.

Third, social behavior.

The herd behavior of pigs refers to various interactions between individuals in the herd. Pairing is a prominent communication activity, and pigs show more physical contact and maintain auditory information transmission. In the absence of pigsty, pigs can live in their own fixed places, showing the habit of settling down and roaming. Pigs live in groups, but they also have competitive habits, such as bullying the weak, bullying the weak and bullying classmates. The bigger the herd, the more obvious this phenomenon is. A stable pig herd forms a hierarchical community structure according to the principle of dominance sequence, and individuals remain familiar and live in harmony. When the stable community structure changes during reorganization, fierce fighting will break out until a new community structure is formed. Pigs have obvious grades and are formed shortly after birth. In the first few hours after birth, piglets will compete for the sow's front nipples, and often the first-born or heavier piglets get the best nipple position. Piglets in the same litter live in groups. When they parted, they were not far from each other. If they are accidentally frightened, they will immediately gather in a pile or run away in groups. When piglets are separated from sows or piglets in the same litter for less than a few minutes, they will be extremely active, scream loudly and excrete feces and urine frequently. Older pigs have similar behaviors when they are separated from their partners. When the grade of pigs was just formed, aggressive behavior was the most common, and the establishment of grade order was influenced by the breeds that constituted this group. Weight, gender, age, temperament and other factors. Generally speaking, pigs with large weight and strong temperament are dominant, older pigs are dominant over younger pigs, and males are dominant over females and castrated pigs. Piglets and new pigs are often ranked second. The determination of group dominance sequence of littermates often depends on the weaning weight. Piglets in different nests will start to fight fiercely when they are fed in parallel, and lie in small groups according to different sources. In about 24 ~ 48 hours, an obvious ruling hierarchy can be formed, which is generally a simple linear pattern. This hierarchical relationship is more obvious in older pigs, especially in the case of restricted feeding. The dominant sequences are vertical, parallel and triangular, and the winner is in the forefront, and eating often occupies a favorable eating position or has priority. In the pig group with similar overall structure, the pigs with large weight are often in the forefront, and the group composed of different breeds is not the individuals with large weight, but the varieties or strains with strong fighting capacity are dominant. After the establishment of the leading sequence, the normal life in the land of peace began. The sharp and loud snorting of the dominant pig and the intimidation formed by the feint of the nose and mouth can replace the fight, and the inferior pig will retreat without a fight.

Fourth, fighting behavior.

Combat behavior includes offensive and defensive, evasive and defensive activities. Fighting behaviors that can be seen in production practice are generally caused by fighting for feed and turf. In addition to competing for feed and turf, the internal confrontation of the newly merged pigs also played a role in adjusting the social structure of the pigs. When a strange pig enters a group, it becomes the target of the whole group of pigs. This kind of attack is usually serious, ranging from skin injury to death. If two mature and unfamiliar boars are put together, there will be a fierce fight between them. They revolve around each other and smell each other. Sometimes, their forelimbs lie prone on the ground, making a low roar and suddenly biting with their mouths. This struggle may last for an hour. Surrender pigs often turn around and howl and flee from the scene of the fight. Although fighting between two pigs rarely causes casualties, one or both sides will cause huge losses. In the hot summer, the fight between two boars often leads to the death of one or both of them due to extreme heat collapse. The fighting behavior of pigs is mostly influenced by the feeding density. When the density of pigs is too high and the space occupied by each pig is reduced, the number and intensity of fights in the group will increase, which will lead to the increase of feeding aggression of pigs. Reduce feed intake and gain weight. This form of fighting is biting each other's heads, and in a herd of pigs, it is biting each other's tails. The newly gregarious pigs mainly compete for the second place, not for feed. Only when the social elements are formed will there be more struggles for food and territory.

Verb (short for verb) sexual behavior

Sexual behavior includes estrus, courtship and mating behavior. Sows can see certain courtship behaviors during estrus, and both males and sows will show some behaviors before mating. The sow in estrus is mainly characterized by restlessness, high and low appetite, soft and rhythmic humming, crawling over other sows, or waiting for other sows to crawl over, and frequent urination, especially when boars are present. In the middle of estrus and sexual desire, when the boar approaches, adjust the buttocks to be close to the boar, smell the head, anus and penis foreskin of the boar, cling to the boar, even climb over the boar, and finally stand still. Accept wild boar climbing. When managers press the back of sows, they immediately produce standing reflex, which is a key behavior of estrus sows. Once the boar touches the sow, it will chase it, sniff its side ribs and vulva, put its mouth between the sow's legs, suddenly arch the sow's ass upward, foam at the mouth, and often make a continuous, soft and rhythmic throat hum. Some people call this unique cry "courtship song", and boars will urinate rhythmically when they are sexually excited. Some sows show obvious mate selection psychology and strong aversion to individual boars, and some sows show excessive sexual behavior due to hormonal imbalance, or are not in estrus, and estrus is not obvious. Because of the relationship between nutrition and exercise, boars often have low sexual desire, or they commit adultery. Keeping boars in groups often leads to stable same-sex behavior, and boars with low social status are often attached to other boars.

Sixth, maternal behavior.

Maternal behavior includes a series of behaviors of sows before and after delivery, such as nesting, breastfeeding and other activities of raising piglets.

female pig

When a sow is near delivery, it usually appears in the form of holding grass and nesting in a pig bed. If there is no grass in the fence, it will have to be represented by hoofing the ground. 24 hours before delivery, sows fidget, urinate frequently, grind their teeth, wag their tails, arch the ground, lie down and constantly change their postures. When giving birth to a child, you usually lie on your side. Choose the quietest time to give birth, usually after 4 pm, especially at night. When the first piglet is born, sometimes the sow screams. When the piglet sucks the sow, the sow's limbs will straighten out and open its nipples, so that the newborn piglet can nurse. During the whole delivery process, the sow is in the state of milking from beginning to end and keeps purring. The nipples of breast milk are full, and even the milk flowing out is easy for piglets to suck. After the sow gives birth, she lies down in a posture that fully exposes her breasts, forming a heat source and inducing the piglets to lie down next to the sow's breasts. When breastfeeding, sows often take the posture of lying left or right, and do not turn around during breastfeeding. Both mother and offspring can actively cause breastfeeding behavior, and the hum rhythm of sows is low. When a piglet is breastfeeding, sometimes the piglet starts breastfeeding by its sound and constant touching of the sow's breast. When a sow is breastfeeding, the cry of sow cubs often causes other sows in the same room to breastfeed. The suckling process of piglets can be divided into four stages. At first, the piglets gathered at the breast, each occupying a certain position, rubbing the breast with its nose and sucking. The piglets leaned back, their tails rolled tightly, and their forelimbs straightened forward. At this time, the sow's snoring reached its peak. Finally, after milking, the pig massaged the breast again and stopped breastfeeding. Mothers and offspring recognize and communicate with each other through smell, hearing and vision, and the cry of pigs is a kind of contact information. For example, the sounds of nursing sows and piglets can be divided into three types according to the different vocal parts (throat or nasal sounds) and sounds, namely, uh-huh sounds (when the mother is intimate with the baby), screams (when the baby is frightened) and mixed nasal and laryngeal sounds (when the mother is nursing the baby). According to these different sounds, mothers and babies can send messages to each other. Sows pay great attention to protecting their piglets, and they are very careful when they walk and lie down, so as not to step on or crush the piglets. When the sow lies down, she chooses to keep discharging her piglets from the lying position with her mouth against the fence triangle, and slowly lies down against the fence to prevent the piglets from being crushed. Once the pig is crushed, as long as she hears the cry of the pig, she will immediately stand up and repeat the back pressure action until the pig is not crushed. When a sow with a young invades the outside world, it will first give an alarm roar. When the pig hears the sound, it will run away or stay on the ground. Sows will open their mouths and threaten or even attack intruders. Sows that have just given birth will show strong aggressive behavior even if they catch piglets from the breeder. These maternal behaviors are particularly obvious in local pig breeds. The maternal behavior of modern breeds, especially the highly selected lean pig breeds, has weakened.

Seven. Activity and sleep

The behavior of pigs has obvious circadian rhythm, and most of them are active during the day, warm season and summer. There are also activities and eating in the evening, and the time for activities in cold weather is shortened. The day and night activities of pigs vary with age and production characteristics. The average rest time of piglets, breeding pigs, sows and fat pigs is 60% ~ 70%, 70% ~ 85% and 70% ~ 85% respectively. The rest peak is in the middle of the night, and the rest is the least around 8 am. The sleep time of lactating sows gradually decreases with the increase of lactation days, and the number of walks is from less to more, and the time is from short to long, which is the unique behavior of lactating sows. There are two kinds of lying-down rest for nursing sows, one is lying down and the other is sleeping. The supine rest posture is mostly lateral, so it is not easy to lie down, and the breathing is light and even. Although the eyes are closed, it is easy to wake up. Sleeping is sleeping on your side, breathing deeply and long, snoring, and often shaking your fur, which makes it difficult to wake up. Within three days after birth, piglets are almost sleepy except for sucking and excreting. With the growth of age and physical strength, activities gradually increase and sleep decreases accordingly. However, after eating a lot of supplements at the age of 40, the sleep time has increased again. Generally, I sleep quietly after eating enough. Piglets generally imitate sows in their activities and sleep. After birth 10 days, piglets in the same litter began to move in groups, with little individual activity. The main performance of sleep rest is collective sleep.

Eight, inquiry behavior

Inquiry behavior includes exploration activity and experience behavior. Most of the general activities of pigs come from exploration behavior, and most of them are aimed at objects on the ground. Through seeing, hearing, smelling, tasting, gnawing, arching and other senses, they show a well-developed exploratory physical strength, which refers to the exploration and investigation of the environment and the interaction with the environment. Pigs are very curious, and they have approached many familiar things in their recent exploration. Piglets are "curious" about everything in the small environment, and they are also very close to their friends in the same nest. The pig's inquiry behavior is obvious. Piglets can stand about 2 minutes after birth and start looking for sows' nipples. Digging with the nose is the main method of inquiry. Another obvious feature of the pig's inquiry behavior is that it bites all new things in the surrounding environment with its nose arch and mouth. It is the main aspect of pig's exploration behavior to fiddle with the surrounding objects with the nasal process, which lasts longer than group play. When looking for food, pigs dig, smell, arch, lick and chew first, and then open their mouths to eat when the bait meets the taste. This feeding process is also an inquiry. Similarly, the order in which piglets suck sows' nipples and the accurate identification between mother and child are also established through the exploration of sense of smell and taste. Pigs can clearly distinguish different areas of sleeping, feeding and excreting in pigsty, which is also formed by distinguishing different smells with their noses.

Nine, abnormal behavior

Abnormal behavior refers to the behavior beyond the normal range, and vice refers to the abnormal behavior that causes harm or economic loss to people and animals, and its production is mostly related to harmful stimuli in the living environment of animals. For example, sows kept in cages for a long time will persistently and stubbornly gnaw at the iron nipples of automatic drinking fountains. Sows live in boring fences or cages and often munch on the posts in front of the cages crazily. Generally, with the increase of the range of restricted activities, the frequency and intensity of column biting will increase, and aggressive behavior will also increase. Pigs with hyperactive tongues often roll up the tip of their tongues and keep stretching in their mouths, and some also have arch addiction and empty chewing addiction. Cannibalism is another harmful habit, such as the phenomenon that neurotic sows eat their young after giving birth. Abnormal behavior of biting tail often occurs in crowded captivity or in nutrient-deficient or boring environment, which brings great harm to production.

X. after-effect behavior

Some behaviors of pigs are innate, such as foraging, sow breastfeeding and sexual behavior, while others are acquired, such as learning to recognize certain things and obey people's orders. Acquired behavior is called conditioned reflex behavior or aftereffect behavior. Aftereffect behavior is gradually established by the familiarity of pigs with new things after birth. Pigs have a strong memory of eating and drinking, and are most likely to establish conditioned reflex on feeding tools, food trough, drinking trough and their orientation. For example, when piglets are artificially breastfeeding, they are fed regularly every day. As long as you train a few times, you can listen to the signal and eat at the designated place. This shows that pigs have aftereffect behavior. Through any training, pigs can establish the reaction of aftereffect behavior, obey people's instructions and achieve the purpose of improving production efficiency.

Classification of local pig breeds

According to geographical classification 1, North China type: Min pig, Huanghuaihai black pig, Richard black pig, Bamei pig, etc. 2. Types of South China: Southern Yunnan Small Ear Pig, Lantang Pig, Luchuan Pig, etc. 3. Central China type: Ningxiang pig, Jinhua pig, Jianli pig, Dabai pig, etc. 4. Jianghai type: the famous Taihu pig (collectively referred to as Meishan and Erhualian); 5. Southwest type: Neijiang pig, Rongchang pig, etc. 6. Plateau type: Tibetan pigs (Aba, Diqing and Hezuo Tibetan pigs).

Large white pig

Large white pig

Also known as "Yorkshire pig". Originally from Britain, it is specially called "British Large White Pig". After being introduced into the Soviet Union, it became a "Soviet white pig" after long-term domestication and cultivation. The latter is stronger than the former, with strong limbs and suitable for grazing. It was cultivated in England in the18th century. Yorkshire pig is a famous pig. Originated in Yorkshire, England (an old county in the northeast of England, 1974 was divided into North Yorkshire, South Yorkshire and West Yorkshire), which was made by crossing local pigs with China pigs. The whole body is white, and the ears stand up forward. There are three kinds, big, medium and small, which are called "big white pig", "medium white pig" and "small white pig" respectively. Large white pig belongs to cured meat type and is the most widely distributed pig breed in the world. When you grow up, adult boars weigh 300 to 500 Jin and sows 200 to 350 Jin. Strong reproductive ability, 10 to 12 litters per fetus. Xiaobai pig is precocious and fattening, belonging to obesity type. The size of Chinese white pig is between the two and belongs to meat type. There are many large white pigs in China.

Landrace

It is the general name of "Landrace Pig" in China. The famous pickled pig breed. Originated in Denmark. It is a cross between a local pig and a large white pig. All white. The body drive is long and streamlined. Long and narrow head, big ears hanging forward, straight back, developed hindquarters, plump thighs and high limbs. Fast growth rate and high feed utilization rate. Thin skin and thin flesh. Eleven to twelve nests per nest. Adult boars weigh 400 to 500 kilograms, and sows weigh about 300 kilograms. Need better feeding and management conditions. All over the world.

Hampson pig

Hampshire sow

It is a famous pig breed. /kloc-At the beginning of the 9th century, it was exported to the United States from Hampshire, England, and crossbred in Kentucky. The coat is black, and the shoulder and neck joints and forelimbs are white. The nose is slightly long and straight, upright. The body is long and muscular Adult boars weigh 3 15 to 4 10 kg, and sows weigh 250 to 340 kg. Early maturity, medium fertility, with an average of eight births per litter. Strong motherhood. Carcass quality is high, and the proportion of lean meat is large.

Bo breeding pig

This is a famous pig. Native to the United States. It is a hybrid of China pig, Russian pig and British pig. Originally a fat type, it has now been cultivated into a meat type. The whole body is black and has the characteristics of six whites. The nose is straight and the ears are drooping. Large, adult boars weigh 390 to 450 kilograms, and sows weigh 300 to 400 kilograms. Early maturity and easy fattening, good carcass quality; However, the fecundity is weak, about 8 per litter.

Horseshoe pig

Horseshoe pig

Mashen pig is native to Shanxi, China. Big body, big ears, drooping nose, long and straight mouth tube, straight and narrow back and waist, sloping hips, strong limbs, dark and thick hair, dense brown-red fluff in winter, and 7 ~ 10 nipples. It can be divided into three types: Malaysian pig (big), Ermayina pig (middle) and bowl pig (small). Although the growth rate is slow, the carcass lean meat rate is high.

Domestic pig breed

Domestic pig

Baelz's 1 pig and No.2 pig (for meat) were bred in the United States. The No.1 pig in Belz is black, and the No.2 pig is red. In Britain, Japan, Australia, New Zealand and South America, Berkshire pigs are medium-sized and mostly black. Chester white pig (used for fat) was bred in Chester County, Pennsylvania. It is large, white, light pink and mild in sex. Dorset Duroc or Duroc Jersey pig (for fattening) in North America and South America is of medium size, with long body length, black 1/2 Jersey pig 1/2 Duroc Hampson pig (for meat) in the United States is of medium size, long body length, black and lively, and it is suitable for grazing and raising Hereford pig (about 1900). Light red to dark red fat Nordic pigs (for meat) are of medium size in Northern Europe, Central Europe and the United States, and there are many white varieties. Maryland 1 Pig (for meat) 194 1 year was bred in the United States. It is a medium-sized black Nordic pig with white spots. 40% Berkshire pigs Minnesota 1, No.2 and No.3 (for meat) were bred in the United States, with different body colors. Montana No.1 pig (for meat) was bred in the United States in 1930s, with a slightly arched back. In 194 1 year, a flat-cheeked hybrid of Nordic pig and Hampton pig was bred in the United States. 1/3 Chester white pig Bozhong pig (meat) was bred in the United States in black, but its legs, nose and tail were white. Bozhonghua pig (for meat) is a white breed cultivated in the United States, but in the United States, Britain, New Zealand, Australia and Canada, its legs are black or it is called spotted pig Bamworth pig (for meat).

Edit the pig raising method in this paragraph.

1 for protective feeding. In summer and autumn, planting gourd, big melon, sleeping melon, sunflower and other plants outside the pig house can shade and cool down. In winter, plastic greenhouse feeding technology should be popularized, and insect repellent and immunization work should be done regularly. 2. Promote high-density pig breeding. 0.8m2 pigpen in winter 1 fattening pig, summer 1 pigpen 1 fattening pig. High-density breeding pigs not only have few laps and low cost, but also fatten pigs compete for food. Sleep without a sports ground, love to gain weight quickly and reduce feeding expenses. After fattening pigs exceed 90 kg, the daily weight gain rate is obviously slow down, and fat deposition is the main factor, so the more you feed, the more uneconomical it is, and the more fat it is, the harder it is to sell. Slaughtering under 90 kg, although the feed utilization rate is high, is uneconomical because of its small weight and low meat yield. Generally, 90 ~ 120 kg slaughter is most suitable for fattening pigs. 4 varieties should be excellent. First of all, we should choose varieties according to market demand. At present, it takes at least three yuan, preferably five yuan, to popularize multiple hybridization For example, the British PIC pig, five lines, has a fast growth rate, and can reach 1 10 kg in 58 days, with a lean meat rate of 66% and a feed-meat ratio of 2.8: 1. Column 5 should be simple. Don't make the pigsty too luxurious, just keep warm and ventilated. 6 feed should be cheap. Feed accounts for 70-75% of the cost of raising pigs. Feed formula should change with the change of market price and season, and cannot be fixed. If pigs eat less in hot summer, the feed should be more nutritious. Feed nutrition should be balanced to meet the growth needs. 7 epidemic prevention should be strict. Pay attention to disinfection, not only to prevent foreign diseases, but also to prevent fecal pollution and spread diseases, and inject vaccines according to immunization procedures. 8 slaughter should be timely. For example, the weight of binary pig reaches 70 kg, the inner ternary 80-85 kg, the outer ternary 95 kg, and the British PIC pig 105 kg is the timely weight of slaughter. In addition, when the pig market price is high, the heavier the weight, the better; When the price is low, it's best to be light, so as to reduce feed consumption and cost. "Feed-back" pig-raising method is a new type of pig-raising method based on the above shortcomings and the growth law and characteristics of pigs. This method is in the stage from piglet to middle pig. That is, before 50-60 kg, concentrate with high energy and high protein is the main material, supplemented by necessary feed additives and a small amount of green feed. From the middle pig to the slaughter stage, the input of concentrated feed should be appropriately reduced, and the ratio of green feed to roughage should be increased: concentrated feed 60%, green feed 25%, roughage 15%. This method not only shortens the feeding cycle of pigs, but also makes full use of a large number of green feed and roughage resources, thus saving the amount of concentrated feed and greatly improving the economic benefits. 10 feeding management: scientifically raise pigs, reasonably mix feed according to different uses, ages and growth needs of pigs, strengthen management, improve hygiene and prevent diseases.

In fact, it evolved from primitive cells and was born like all animals in the world.